presentations:
find a marine mammals species and make a 15 min presentation on what it is and all that shit
30% of total grade
no more than 15 slides (1 slide per minute) → total 15 min presentation
grades on slides and presentations
written exam: 11th of april
mcq
short answers
long answers
6 questions with sub questions
one question can be about one whole chapter
70% of total grade
emerged abt 50 million years ago
more than 132 living species
main differences between terrestrial and aquatic mammals; the more time they spend in the water, the greater the adaptation to:
gas exchange → inability to exchange lung gases at all times
increased rate of integumentary heat loss
integumentary system includes the skin, hair, and blubber. So when compared to terrestrial mammals, marine mammals lose heat faster to the water compared to terrestrial mammals losing heat to the air, as water is a good conductor for heat. But they adapted to that, e.g. blubber.
relative weightlessness
greater resistance to movement
changed sound propagation
low light conditions underwater
consists of 92 species
two suborders:
Mysticetes → 16 species
Odontocetes → 76 species
altogether has 13 (14) families (1 is extinct → yangtze river dolphin)
can range from 1.2 m to 33 m in length
varying weights across species
small to very long lifespans
can be marine or freshwater
can be solitary or social
may migrate or stay in local habitat
can be found around the world, from the polar caps to the equator
adaptations:
rapid gas exchange - hold breath for a long time
thick layer of blubber and vascular heat-exchange system
blubber → insulation, energy storage, buoyancy control, streamlining
vascular heat-exchange system → uses countercurrent heat exchange to conserve or release heat depending on the environment
big sizes support own weight
smooth skin, rigid bodies, internal genitalia, lack of hind limbs - reduce drag, strong tails to move, dorsal fins for stability
sophisticated sound producing and processing systems
low light conditions → echolocation
BUT: huge difference among species and groups
these are baleen whales
Only baleen whales have two blow holes; that’s how to distinguish them from other whales
the grey whales used to a be a separate family of their own
characteristics:
baleens - filter feeders: gulp feeders, skim feeders, bottom feeders …
2 blowholes
large size (largest mammal)
females are approximately 5% larger than males
streamline bodies
solitary mammals
long migrations between feeding and breeding grounds
low frequency sound production
long distance communication
no sound transmission in lower jaw (like toothed whales) (bone conduction)
functional vomeronasal organ (detects chemicals)
family Balaenidae - 2 genera, 4 species
genus Balaena
bowhead whale
genus Eubalaena
north Atlantic right whale
north pacific right whale
southern right whale
characteristics:
arched jawline
huge mouth
longest baleens = 4 m,
feeding by continuous streaming water through open mouth
no dorsal fins
slow swimmers
biggest testis - sperm competition
Family Neobalaenidae / Cetotheriidae - 1 genus, 1 species
pigmy right whale “living fossil”
smallest of the ballen whales (6.45 m), sleeker, falcate dorsal fin, arched jawline
not well studied, not many sightings, population unknown
Family Balaenopteridae (Rorquals) - 3 genera, 11 species
rorquals “gulp feeders”, ventral grooves, huge tongue
genus Balaenoptera
blue whale
fin whale
sei whale
bryde’s whale
eden’s whale
omura’s whale
rice’s whale
common minke whale
southern minke whale
genus Megaptera
humpback whale - longest flippers “wings”
genus Eschrichtius
grey whale - bottom feeder, use tongue to suck in food, short strong baleens
used to belong to old family called Eschrichtidiidae
characteristics:
teeth - feed on fish / squid / warm blooded animals
one blow hole (left side) - right blow hole is a sound producing organ
echolocation
melon head - sound production
variable in size, males are larger than females (except some beaked whales, Cephalorhynchus dolphins and porpoises)
social group
local and migration
one extinct family → Lipotidae (Yangtze river dolphin)
Family Physeteridae - 1 genus, 1 species
sperm whale → max 18 m long, weighing 60 tonnes
Family Kogiidae - 1 genus, 2 species
pygmy sperm whale → 3.8 m, 500 kg
dwarf sperm whale → 2.7 m, 300 kg
Family Monodontidae - 2 genera, 2 species
Narwhal → 3.5 - 5 m, 800 - 1600 kg, male’s tusk 1.5 m long
beluga → 3.9-4.8 m, 1.3-1.9 tonnes
family Ziphiidae - Beaked whales, 6 genera, 22-24 species
deep divers, sexual dimorphism (females are larger than males), males teeth are tusk-like (sexual selection features), 4-16 m, 1-15 tons, nomedian notch on fluke (flukes are not like mysticetes)
Mesoplodon e.g. strap-toothed whale
Ziphius e.g. Cuvier’s beaked whale
Berardius e.g. Baird’s beaked whale
Tasmacetus e.g. Shepherd’s beaked whale
Indopacetuc e.g. tropical bottlenose whale
family Delphinidae - marine dolphins, 17 genera, 37 species
Orcinus - killer whale
Globicephala - Long-finned pilot whale
Pseudorca - false killer whale
Feresa - pygmy killer whale
Peponocephala - Melon-headed whale
Orcaella - Irrawaddy dolphin
Sotalia - Tucuxi
Sousa - indo-pacific humpback dolphin
Lagenorhynchus - Atlantic white sided dolphin
Grampus - Risso’s dolphin
Tursiops - bottlenose dolphin
Stenella - pantropical spotted dolphin
Delphinus - common dolphin
Lagenodelphis - Fraser’s dolphin
Lissodelphis - Southern right whale dolphin
Cephalorhynchus - Commerson’s dolphin
family Planktanistidae - 1 genus, 1 species
south asian river dolphin
family Iniidae - 1 genus, 1 species
amazon river dolphin
araguaian river dolphin
bolivian river dolphin
family Lipotidae - 1 genus, 1 species (EXTINCT)
yangtze river dolphin
died out in 2002
family Pontoporiidae - 1 genus, 1 species
Franciscana (la plate dolphins)
family Phocoenidae - porpoises, flattened, spade-shape teeth, lack of pronounced beak, 3 genera, 8 species
Neophocaena -
indo-pacific finless porpoise
east asian finless porpoise
yangtze finless porpoise
phocoenoides -
dall’s porpoise
Phocoena -
harbour porpoise
vaquita (nearly extinct)
Burmerister’s porpoise
spectacled porpoise
characteristics:
fully aquatic, herbivorous mammals, with their strong lips pull out seagrass
consumes 10-15% of their body weight per day
inhabits swamps, rivers estuaries, marine wetlands, and coastal marine waters in North America, South America, Africa, and Asia
2.5 and 4 m, 1,500 kg
longevity 50 to 70 years
females give birth only a few times during their lives ad invest considerably
mothers care for the young
2 families:
manatees
dugongs
family Dugongidae - 1 genus, 1 species
dugong
bottom feeders often on seagrass, pointy tails
family Trichechidae - 1 genus, 3 species
African manatee
Amazonian manatee
west indian manatee
plant eater in water column
3 families
Odobenidae (only living member is the walrus)
Otariidae (the eared seals: sea lions and fur seals)
Phocidae (the earless seals, or true seals)
family Odobenidae - 1 genus, 1 species
walrus
no external ears
tingue suction feeders
feed on bottom marine organisms
male: 3 m, 1200 kg
female: 2.2 m, 560 kg
populations: Atlantic ocean, pacific ocean, and laptev sea
age: 20-30 years
migration between ice (pupping) - feeding areas
predators: killer whale and polar bears
family Otariidae - 7 genera, 15 species
these are eared seals
semi-aquatic lifestyle
subpolar, temperate, and equatorial waters in Pacific and Southern Ocean, southern Indian and Atlantic Oceans
absent in the north Atlantic
less adapted to sea life than phocids
can turn hind limbs to walk on land
have external ears
profound sexual dimorphism (males weigh 2-6 times more than females)
shorter and shallower dives
subfamily Archtocephaline (fur seals) - 2 genera, 9 species
genus Arctocephalus (8 species)
genus Callorhinus (1 species)
subfamily Otariinae (sea lions) - 5 genera, 6 species
genus Eumetopias
genus Neophoca
genus Otaria
genus Phocarctos
genus Zalophus
family Phocidae - 14 genera, 18 species
characteristics:
no ears
mostly aquatic, return to land or pack ice to breen and give birth
deep long dives
1.1 - 5.8 m
45 - 5000 kg (male southern elephant seals)
subfamily Monachinae - southern seals, 7 genera, 8 species
Monachus
Neomonachus
Mirounga
Ommatophoca
Lobodon
Hydrurga
Leptonychotes
subfamily Phocinae - northern seals, 7 genera, 10 species
Cystophora
Erignathus
Phoca
Pusa
Pagophilus
Histrophoca
Halichoerus
family Mustelidae - weasels and otters (1 species)
pacific ocean, nearshore water
males: 22-45 kg, 1.2-1.5 m
females: 14-33 kg, 1-1.4m
no blubber but densest thickest fur in the animal kingdom
although it can walk on land, the sea otter is capable of living exclusively in the ocean
gives birth in water
lifespan: males are 10-15 years, females are 15-20 years
eurasia, asia, north Africa
lakes and rivers
lives along the coast in salt water, but requires regular access to freshwater to clean its fur
lives in dents on land, close to water
mating and birth on land
57 to 94 cm long, tail of 35-45 cm
7-12 kg
age: 8-13 years
family Ursidae - bears, 1 species
19 populations in the arctic, need pack ice to hunt seals
considered marine mammals because of their dependence on marine ecosystems
prefer annual sea ice but live on land when ice melts in summer
males 2-2.5 m, 420-500 kg
females 1.6-2.5 m, 150-300 kg
white fur is thick and water repellent, below is black skin
5-10 cm blubber layer
age: 25-30 years
distribution of marine mammals today, ranges of distribution and migrations
importance of water temperature as geographical limits
prey abundance
birthing places
polar to equator (most)
circumpolar (bowhead)
equatorial (bryde and omura)
local (humpback and fin population in Mediterranean sea)
cosmopolitan (blue, fin, sei, humpback)
some migrate (only males in sperm whales)
some migrate circumpolar (narwhal and beluga)
equatorial (some dolphins, short-finned pilot whales)
anti-tropical (ziphiids, long-finned pilot whales)
cosmopolitan (killer whales, sperm whales but local populations)
coastal (porpoises, river dolphins, indo-pacific bottlenose dolphins)
tropical, subtropical dugongs - marine mantaees tied to freshwater
access to abundant aquatic plants
coastal areas and river (amazon manatee is entirely freshwater)
north pacific, fragmented due to over exploitation, no resettlement
nearshore areas due to benthic prey
circumpolar
close to northern phocid seals, primary prey
depend on sea since for hunting
cool temperature and subpolar
popping and mating areas close to shore
absent north Atlantic
polar (crabeater seal)
some non-migratory (ringed seal)
ice adapted (birth on ice)
highly migratory (elephant seals)
freshwater (baikal, caspian seal)
warm water (monk seall)
distinct northern circumpolar
due to hunting, the population is reduced